title: Evaluation of four commercial biuret reagent kits of serum total protein by the American Association for Clinical Chemistry reference measurement procedure.
abstract: BACKGROUND
  In China, the traceability of clinical chemistry methods is still immature. Therefore, it is necessary to establish a reference measurement procedure and evaluate commercial reagent kits using such established procedures.
  
  
  METHODS
  We reproduced the reference measurement procedure for serum total protein, as recommended by the American Association for Clinical Chemistry (AACC). We evaluated the performance by Clinical Laboratory Standard Institute (CLSI) guidelines EP15-A and EP6-A. Subsequently, four commercial reagent kits were evaluated by the reproduced reference procedure following CLSI guideline EP9-A2.
  
  
  RESULTS
  The performance of the reproduced reference procedure was as follows: CVs ranged from 0.47% to 0.85% at medical decision levels (X(c)) of 45 g/L, 60 g/L and 80 g/L. Linearity was Y=1.0022X-0.2121 (r=0.9999), and recovery ranged from 100.2% to 102.4%. The External Quality Assessment Scheme for Reference Laboratories in Laboratory Medicine (RELA) was applied, and the result was within the limit of equivalence. The linear relationships of four commercial reagent kits, Merit Choice, KHB, Leadman, and Olympus, were, respectively: Y=0.9922X+0.5776 (r=0.9961); Y=0.9936X+0.4316 (r=0.9992); Y=0.9949X+0.9129 (r=0.9987) and Y=0.9923X+0.8876 (r=0.9989). KHB showed slight negative bias, and the mean±SD was -0.03±0.60 g/L. Merit Choice, Leadman, and Olympus all showed positive bias, and the mean±SDs were 0.02±0.63 g/L, 0.55±0.77 g/L and 0.34±0.71 g/L, respectively.
  
  
  CONCLUSIONS
  The correlation and bias of four commercial reagent kits for serum total protein were found to be acceptable. Thus, these reagent kits can be used reliably in China.
authors.affiliation: Department of Laboratory Medicine, Peking University Third Hospital, Beijing, P.R. China.
authors.forename: Meilin
authors.initials: M
authors.lastname: He
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
mesh_terms: D001738:Biuret Reaction / Q000592:standards*; D001774:Blood Chemical Analysis / Q000592:standards*; D001798:Blood Proteins / Q000032:analysis*; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D012952:Societies / Q000592:standards*
chemical_list: D001798:Blood Proteins